Real estate mogul and reality television star Donald Trump announced today he would not seek the Republican nod to challenge President Barack Obama in 2012, quelling months of speculation.

Real estate mogul and reality television star Donald Trump announced on Monday he would not seek the Republican nod to challenge President Barack Obama in 2012, quelling months of speculation.

"After considerable deliberation and reflection, I have decided not to pursue the office of the presidency," Trump said in a statement. "Business is my greatest passion and I am not ready to leave the private sector."

Trump, 64, had openly flirted with a presidential run over the past few months and courted controversy by embracing discredited charges that Obama had concealed his birth certificate to hide that he was foreign born and thus ineligible for the White House.

Public opinion polls had shown him running strong among a weak Republican field even though the US political establishment and pundits generally did not take him seriously.

"This decision does not come easily or without regret," said Trump.

"I maintain the strong conviction that if I were to run, I would be able to win the primary and ultimately, the general election."

Trump was the second high-profile potential candidate in days to rule out a Republican White House run after former Arkansas governor Mike Huckabee, a particular favorite of religious conservatives, said over the weekend that he would not seek the party's nomination.